The Warren and Harris stories are similar to each other, when viewed using the data described here. Both are trending upwards from a respectable just under two digit position, menacing those in second place.
I put the polynomials (third order) on there to investigate consistency in this trend over time. They show that Warren’s upward trend is steady, and Harris’s is more stepwise. It is hard to know if this means one is stronger, or rising faster, or more likely to take a top position, than the other. Not shown here, but looking at only the last month or so, both trend up, and Harris overtakes or equals Warren 20 days out. But, the variance in the data for that shorter time period is high, so I wouldn’t put much in it.
Bottom line: Harris and Warren are moving into position to be contenders in the race for the Democratic Party nomination, currently moving past, or about to move past, second place Sanders, while at the same time Biden is sinking into the same range. For a brief moment, this may be a four way horse race, by the end of July or early August.